[masraum]

Originally Posted by oldE

The dams were indeed constructed for the very reasons you enumerated. However there were costs (there always are) not considered. Fish passages may or may not have been designed in, but even if they were, the higher and farther a fish has to go to transit such a structure, the less likely it is to complete the trip, resulting in species loss.
As many dams, with greater or lesser utility reach their end of life, there are often compelling arguments for habitat restoration.

Best
Les

Right, and besides the obvious ecological issues, many times dams have more direct human impact often submerging homes and in same cases, villages. I'm sure folks in the US have had to move, but I know that I've heard of damns in foreign countries submerging villages, often multiple villages, and sometimes ancient/archeological sites.